| 摘要 |
PURPOSE:To enable separate measurement of the surface recombination velocity on one surface of the semiconductor wafer, the surface recombination velocity on the other surface thereof and a bulk life time, by measuring the change of electrical conductivity caused by the application of light beams. CONSTITUTION:Impulse beams 2 generated by the light beams or electron beams are applied on one surface 1A of the semiconductor wafer 1 and the time change delta(t) of electrical conductivity of the semiconductor wafer based on excessive carriers excited instantaneously by the application is measured. Likewise, the light beams or electron beams 2 are applied on the other surface 1B and thereby the time change of electrical conductivity based on the different spatial distribution of the excessive carriers is measured. A value logdelta(t) after the passage of sufficient time forms a straight line, and the bulk life time and the surface recombination velocity are determined independently from the tilt h thereof and from the value delta1(0) of extrapolation value of the straight line to t=0, respectively. |
